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Old 01-22-2017, 11:55 PM   #251
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House Battery Charging Observations

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Originally Posted by michaelf View Post
Hey Tim, no comments on the idle...but questions about your battery levels and consumption. You have 2 x 100W panels and the standard 200Ah battery, correct? YES Guessing your draw is the 'normal stuff' like the fridge, lights, laptops/phones, the Espar fan, and water pump. YES What is the daily battery draw vs the regen from the panels you've been experiencing on this trip? We'll often be using our van like you are on this trip.

I'm doing the 2 x 100W panels + considering the portable 80W panel. With the kids and the constant fridge use, tablets being used, stereo running, etc...just trying to get a real world idea if I'm going overkill on the panels (or will need a 2nd battery). I'm assuming we'll be getting about the same sun exposure, even in summer in the Sierras, while camping in the shade of the pine trees. I'm not a math guy, can rewire a house, but get easily confused on solar/house battery consumption, water pump draw, etc. Any suggestions or advice for my build would be greatly appreciated! TIA
Michael,

I wish you had asked this question sooner, or that I had been smart enough to think of it myself! The days spent at Quartzite would have been perfect for logging what was happening in an organized fashion. But I didn't think of it in time, thus you will have to settle for some general observations. As to the electrical math side of it, there are others here much better versed in that than I, hopefully someone will chime in with the numbers in order to help you determine your needs. If not, I'm happy to sit down with you to add up all of the loads and see where that puts you.

From the Page 33 of the owners manual (dated 2010) that came with my 2016 SMB:

- The alternator will only charge the auxiliary battery to 85-90% capacity. You must connect to shore power or confirm solar panels are charging the auxiliary battery.
- To help lengthen the life, only discharge the battery 50% or about 12.2 volts. Then fully charge within 48 hours...voltage of a fully charged battery is 12.8 volts.

From the Zamp Solar Charge Controller manual the information can be extracted that Bulk Charge is the maximum current charging state, taking the house battery from 11.5 volts to 12.5 volts, or up to 85% capacity. After this stage comes the float stage, this is a slow, lower-voltage charge that takes time and is best accomplished with the battery charger connected to shore power or with the solar input. Bulk charge is easily accomplished with the engine running and the alternator charging, either while driving or with the high idle set at 1,500 rpm for maximum alternator output.

Here's where I wish I had logged the data.....

It was fairly cold this past week in Quartzite, with lows in the mid to high 30's and highs in the high 50's. We would wake up to the battery at 12.3 volts and I would start the engine and set the high idle at 1,500 rpm for 30 minutes in the morning. During this time the Espar heated water and the thermostat was kicked up to 70, the water pump was run a bit, several lights were on and electricity was used to heat water for tea (12 volt one-cup immersion heaters, they work great!) With all this use and the engine running the house battery came up to 12.5-12.6 volts

We were there for four days and of those four there was only one that was sunny enough for the solar panels to get the battery into the float charge state and thus fully charged.

Our evening routine was fairly similar, about three hours of lights, stereo, two i-Phones being used and charged, and the Espar on to take the chill off. At the end of this time the battery would be down in the 12.3 volt range and I would start the engine and run the high idle for 15 to 30 minutes. This brought the voltage back up to 12.5-12.6, I would set the Espar down to 60 degrees and we would retire for the evening. (Also, it should be noted that we start the engine and set the high idle anytime we use the microwave, plus the refrigerator runs on 12 volt power, there is no propane in our build.)

After Quartzite we headed for the Palm Springs area and the San Jacinto Mountains and we got back to our "normal" routine with quite a bit of driving during the day prior to shutting things down for the night. In this scenario the voltage would typically read 12.7 when the engine was shut down, we would use power for about three hours and see it drop to 12.4-12.5 volts, I would run the high idle for 15 minutes or so, and when we got up in the morning it would read 12.4-12.5 volts.

It is worth noting that it was quite a bit cooler at night in Quartzite and thus more draw on the Espar to keep the van temperature at 60 degrees. There is also quite a bit of literature out there on the effect of cold on batteries, worth considering if you plan on much winter time use.

You mentioned considering a 2nd house battery. I explored this when planning the build and was told that if I wanted a second 4D battery it would have to go inside, that there wasn't room for it anywhere under the van. For me this was a deal-killer as I didn't want the battery inside, but I urge you to get in contact with Chris in Santa Rosa as I recall that he mounted an additional battery under the van on the passenger's side (the standard location is on the driver's side), something SMB Texas told me they couldn't do.

Would that second battery be nice? Of course it would. Will you and your family most likely use more power that Laura and I? I suspect so. But for Laura and I having one 4D battery and using the high idle within the parameters I described in Post 248 works just fine for us. As you may recall, my van is pre-wired for the portable panel and that remains an option for us but if we are going to be sitting for an extended period I will either bring along the Honda 2000 generator or just run the high idle charging sequence once or twice a day. One thing I feel confident saying is that with the conditions we experienced in Quartzite this past week (winter conditions, low sun angle, short days, lots of cloud cover) there is no way that the solar panels alone would have been sufficient to keep the batteries charged.

Sitting on my workbench in the garage is the Magnum inverter/charger Battery Monitor Kit (ME-BMK). (This is an SMB option, I suggest you have it installed as part of your build, I wish I had.) Once I install this it will making monitoring the system much easier, something I recognized I wanted/needed almost immediately after picking up the van. I guess I've been putting off getting much more into the details of the system until I have this installed. I know that's not much of an excuse, but it's the only one I have!

I hope this helps and doesn't just serve to confuse you all the more. I can discharge the battery and measure the amp hours the two panels put in over the course of a day, that would give you much more to go on. I want to say 28 amp hours was the best day we had in Quartzite, but that's trusting my memory, sometimes not a good thing to do....
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Old 01-23-2017, 10:43 AM   #252
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Michael & Fitz,

One thing to consider is getting a second alternator (easiest to do when ordering new) for the house bank. I ordered my van with the 2nd factory alternator bracket, & high idle and picked up the Nations 270 amp alternator (already had the balmar smart regulator as a spare for my sailboat). The advantages include:

1. The smart regulator on the 2nd alt will adjust the current and voltage to fully charge the house bank in less time than you can partially charge with the stock alternator. Because the stock setup is charging both the starter and the house banks, is has to reduce the current and voltage to not overcharge the starter batt long before the house bank may be full. That's likely the reason why the manual says the alt will not fully charge the house bank.

2. Having a dedicated charging source that is voltage, current and temperature corrected for the house bank will charge it better, faster, and prolong its life.

3. Idling without a sufficient load wears down Diesel engines, so adding some load and shortening charging times is preferable; and

4. It's nice to have a redundant system if you are boon-docking. Granted, I've sailed for weeks without land in site, so I may be a little more paranoid about system failure than some.
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Old 01-23-2017, 07:49 PM   #253
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Beached,

Really good comments, thanks for the input.

My van is set up for the second alternator so that is an option down the road. I like the flexibility it affords but the location down low on the engine is a bit of a put off. We got into some serious rain this past week and found ourselves in about a foot of water with no option but to drive through it - not a problem with the single alternator but I have to wonder how the second alternator mounted down low would have fared with all of the water splash it would have been subjected to.

The stock 4x4 van is rated for 24" of wading depth. I went back and looked, Snowy said the second alternator on his Sprinter sitting on 285/70R17's lowers this limit to 17". Something to be aware of if there is water in your future!

All in all, I really like the options that are available and the final solutions we all find for our particular needs. The small amount of high speed idling we will do will be more than offset with plenty of time at speed, for me an acceptable compromise. I thought I would be packing our Honda 2000 generator all around with us, but at this point I see it as an optional accessory that will only be brought along on an as-needed basis.
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Old 01-23-2017, 11:45 PM   #254
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Tim and Beached, thanks for the info. Detailed as usual and much appreciated.

I'm guessing my normal electrical use will be a bit heavier than yours Tim....kids with tablets and the constant opening of the fridge for food. Probably less heater fan but more water pump. Sounds like the portable 80W panel will be needed to keep the battery topped off through the day for evening use. We'll be mostly fair weather campers with the kids and doing the high idle with the microwave once or twice a day anyhow. Solo and guys trips will be a completely different story but I'm guessing much less electrical draw since the beer lives in the Yeti anyhow.

I'd planned on getting the Battery Monitor Kit, already got the spec sheet from Nick at SMBW. Going forward I'll have to (get some help!) to crunch some numbers with regards to the 2nd battery. Sounds like the extra solar is the first step, not too sure about the need for the extra storage though. Ordered the van with the 2nd alternator mount and high idle just in case. Like you, I'd rather not go with the etra alternator. Trips where we'll drive often will be fine, it's the longer extended stays that I'm trying to plan for.

Sorry for the thread drift. I know your build is similar to ours (no propane, diesel water/heat, portable cooktop, micro, etc) so your real world use seems to mirror mine best compared to most vans out there. Anyhow, glad Fitz is working out well. I might have to beg ya for more info on the table setup, my wife was looking at it the other night with much envy. The greatest exercise in patience I've ever dealt with......
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Old 01-27-2017, 11:27 AM   #255
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Quote:
Originally Posted by Fitz View Post
Beached,

Really good comments, thanks for the input.

My van is set up for the second alternator so that is an option down the road. I like the flexibility it affords but the location down low on the engine is a bit of a put off. We got into some serious rain this past week and found ourselves in about a foot of water with no option but to drive through it - not a problem with the single alternator but I have to wonder how the second alternator mounted down low would have fared with all of the water splash it would have been subjected to.

The stock 4x4 van is rated for 24" of wading depth. I went back and looked, Snowy said the second alternator on his Sprinter sitting on 285/70R17's lowers this limit to 17". Something to be aware of if there is water in your future!

All in all, I really like the options that are available and the final solutions we all find for our particular needs. The small amount of high speed idling we will do will be more than offset with plenty of time at speed, for me an acceptable compromise. I thought I would be packing our Honda 2000 generator all around with us, but at this point I see it as an optional accessory that will only be brought along on an as-needed basis.
What's the issue with the alternator and water crossings? We'll have a 2nd alternator and a skid plate to protect it. I'm not sure how this would reduce the fording depth unless I missed something with snowy's post? Alternators can be submerged just fine. If you are repeatedly submerging it in muddy water, you may shorten the life (like jeeps that are built for off roading), but occasional short water crossings are totally fine.
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Old 01-27-2017, 01:27 PM   #256
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Wrinkledpants,

What I got from Snowy's comment was that he felt that submerging the alternator was not to be done and that he was setting his water fording depth limit based on the constraint of not submerging the alternator. It made sense to me so I went with it.

Has anyone here with the second alternator submerged it? If so, any adverse effects from doing so? It would be great to have someone with actual experience with this specific installation weigh in. When I was at Van Compass having them install the skid plate package they told me of a customer who shorted out the second alternator due to snow packed around it (the customer replaced the alternator and had the skid plate installed by Van Compass to protect it), but I haven't heard anything beyond that related to damage from water.
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Old 01-27-2017, 01:37 PM   #257
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If it's packed with snow and overheats - that will be one way to quickly end the life of your alternator. Our cayenne has a liquid cooled alternator to help extend the life and have better control over the output, regardless of ambient temps.

I guess I've never heard of submerging an alternator as being bad. People have been doing it for years without issue as jeeps, FJ's, land rovers, etc - they all have exposed alternators designed just like both alternators on the van. Lots of water can shorter the bearing life, and debris in the water can get lodged in the alternator if you're not careful.

But, as far as crossing a stream and submerging the alternator - there is no issue there.
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Old 01-27-2017, 05:19 PM   #258
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Wrinkledpants,

GREAT info to know, thank you. I have no experience with submerging an alternator, now you're making me want to go out and try it!
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Old 01-27-2017, 07:23 PM   #259
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Been enjoying following this thread for quite some time now, quick opportunity to say thanks for all the info shared here.

This new thread "Water Crossings" might be a place where more will be shared further to the subject of last few posts here. FYI: http://www.sportsmobileforum.com/for...tml#post195466

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Old 01-27-2017, 09:54 PM   #260
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PvT,

Thanks for the kind words. When I started this (my first Forum and my first attempt at anything like this) I decided I wanted to do my best to share along the way. I have gotten so much from all the members here it seems the least I can do to give back a little.

I still have a few things to add over the next couple of months, stay tuned!
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